0x20 issue with GPS

[grayal]

The 0x20 issue is an intermittent update issue with the GPS, I've not looked at the firmware of the microcontroller doing the parsing and i2c comms to see where the issue could be. For now just swallow it and add a confidence level to the output that goes down on each update that includes an error and resets on a clean update.

Proper fix is to stress test i2c channel with GPS comms, diagnose if failure on pi or gps end and fix.